Button Prefab

Checked with version: 5.4

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Difficulty: Intermediate

In this live training we will learn the updated workflow for creating and populating scroll-lists at run time using the Scroll Rect interaction component. We will use this to create a simple two column shop where items can be bought and sold between two lists. A Scroll Rect can be used when content that takes up a lot of space needs to be displayed in a small area. The Scroll Rect provides functionality to scroll over this content.

SimpleObjectPool

Code snippet

using UnityEngine;
using System.Collections.Generic;
// A very simple object pooling class
public class SimpleObjectPool : MonoBehaviour
{
// the prefab that this object pool returns instances of
public GameObject prefab;
// collection of currently inactive instances of the prefab
private Stack<GameObject> inactiveInstances = new Stack<GameObject>();
// Returns an instance of the prefab
public GameObject GetObject()
{
GameObject spawnedGameObject;
// if there is an inactive instance of the prefab ready to return, return that
if (inactiveInstances.Count > 0)
{
// remove the instance from teh collection of inactive instances
spawnedGameObject = inactiveInstances.Pop();
}
// otherwise, create a new instance
else
{
spawnedGameObject = (GameObject)GameObject.Instantiate(prefab);
// add the PooledObject component to the prefab so we know it came from this pool
PooledObject pooledObject = spawnedGameObject.AddComponent<PooledObject>();
pooledObject.pool = this;
}
// put the instance in the root of the scene and enable it
spawnedGameObject.transform.SetParent(null);
spawnedGameObject.SetActive(true);
// return a reference to the instance
return spawnedGameObject;
}
// Return an instance of the prefab to the pool
public void ReturnObject(GameObject toReturn)
{
PooledObject pooledObject = toReturn.GetComponent<PooledObject>();
// if the instance came from this pool, return it to the pool
if(pooledObject != null && pooledObject.pool == this)
{
// make the instance a child of this and disable it
toReturn.transform.SetParent(transform);
toReturn.SetActive(false);
// add the instance to the collection of inactive instances
inactiveInstances.Push(toReturn);
}
// otherwise, just destroy it
else
{
Debug.LogWarning(toReturn.name + " was returned to a pool it wasn't spawned from! Destroying.");
Destroy(toReturn);
}
}
}
// a component that simply identifies the pool that a GameObject came from
public class PooledObject : MonoBehaviour
{
public SimpleObjectPool pool;
}